Everyone is hooked on something.
It's not that easy to kick the money habit. After the world meltdown forces London's bankers to go cold turkey, people look elsewhere for a quick quid: the old fashioned East End.
So when investigator Catherine Berlin gets an anonymous tip-off about a local loan shark, the case seems straightforward – until her informant is found floating in the Limehouse Basin.
In another part of town, a notorious doctor is murdered in his surgery, and his entire stock of pharmaceutical heroin stolen. An unorthodox copper is assigned to the case, and Berlin finds herself a reluctant collaborator in a murder investigation.
Now Berlin has seven days to find out who killed her informant, why the police are hounding her and, most urgently of all, where to find a new – and legal – supply of the drug she can't survive without.